Network-selecting device



0.. B. JACOBS.

NETWORK SELECTING DEVICE.

APPLICATION FILED MAY I7, I9I94.

i 1,355,147, Patented oct. 12,1920.

2 SHEETS-SHEET 1.

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A TTORNE Y NETWORK sELEfzHNf. ofvlcE.

APPLICATION FILED MAY i7. 1919.

P11-muted Oct. 12, 1920.

2 SHEETS-SHEET 2.

UNITED STATES PATENT OFFICE.

. OLIVER B. JACOBS, 0F EAST ORANGE, NEW JERSEY,',ASSIGNOR T0 AMERICNTELE- PHONE AND TELEGRAPH COMPANY, A. CORPORATION OF NEW YORK.

NETWORK-SELECTING DEVICE.

Specification of Letters Patent.

Patented Oct. 12, 1920.

T o all whom it may con-cem:

'Be it known that I, OLIVER B. JACOBS, residing-at East Orange, in thecounty of Essex and State of New Jersey, have invented certainImprovements in Network- Selecting Devices, of which the following is aspecification.

This invention relates to telephone repeaters and more particularly to ameans for automatically selecting a suitable artificial line or networkfor balancing a line or trunk with which a repeater may be associated.

It is one of the objects of the invention to provide a repeater which issuitable for making connections with any one of a number of transmissionlines although the impedance of such lines be widely different. Anotherobject consists in equipping a repeater with a. plurality of balancingnetworks or artificial lines of different impedance characteristics, andproviding means whereby any one of said networks may be connected to therepeater. Another object consists in the provision of means forautomatically selecting the proper network .to be connected to therepeater when the repeater is associated with a transmission line. Afurther object consists in the provision of means for preventing falseselection and for preventing other repeater apparatus from interferingwith the network selecting process while it is in operation. Other andfurther objects of the invention will be clear from the detaileddescription to be given later.

It has heretofore been customary when a connection is made between twotransmission circuits through a repeater, to provide a balancingartificial vline or network for each circuit. In some cases thesenetworks are associated with the repeater circuit and in others with thetransmission circuits. In

the first case, if the repeater circuit is used with other types oftransmission circuits having different characteristics, the networksnormally associatcd with. the re-` peater must be replaced, by manualmeans, with others having the proper characteristics. vIn the secondcase, when the repeater is connected to different transmission circuits,the proper network which is associated with each transmission circuit isconnected to the repeater at the same time the connection is made to thetransmission circuit. yThis latter arrangement has the disadvantage ofrequiring two switchboard Jacks for each transmission circuit, one forthe'transmission circuit itself, the other for the. network, togetherwith a twin plug associated with the repeater whereby the conu nectionis made to both the transmission circuit and the network by oneoperation.

It has the further disadvantage of -requiring as many networks asthereare transmission circuits to which the repeater circuit may beconnected. It is proposed by the present invention to provide automaticmeans, which shall operate when a repeater is associated with a giventransmission circuit to associate with the repeater a network o f a typesuitable for balancing such transmission circuit, which will not possessthe above disadvantages.`

There is associated with the cord vcircuit repeater of this invention aplurality of types of artificial lines or networks of differentimpedance characteristics, each of said networks being suitable tobalance one of the .types of transmission lines with which a connectionmay be desired. These networks are associated with the repeater windingsby conductors which branch off from each other at the front and`loa'ckcontacts of several parallel series of network relays. Associatedwith the repeater are a series of controlling relays and controllingconduc- 'may only be actuated when the selecting apparatus at the otherrepeater is not functioning. By the above means a suitable network maybe automatically selected and connected to the repeater cord circuit tobalance the transmission line with which a connection is made, andtheselecting process will be free from interference with the selectingapparatus vof other repeaters.

The invention may now be more fully understood with reference to theaccompanying drawing, Figures l and 2 of which,

. the preferred form of the invention. The

. process of selecting networks.

cord circuit repeater R through which a connection may be desiredincludes the answering and calling plugs P1 and P2, -revspectively, andthe repeater ,elementsV R1 and R2. The repeater elements R1 and R2 areherein illustrated as of the mechanical type although any other wellknown type such as the vacuum bulb repeater may be employed. Adapted tocoperate with the '2 are shown the jacks J1, J2, J1 J2',

lug g2, J2, J7 and J2, at which. terminate the transmissionlines L1, L2,L21, L1, L5, L11, L2 and Ls respectively. As the impedancecharacteristics of these transmission lines with which connections mayhe desired may differ widely, there is provided in the apparatusassociated with the cord circuit repeater R a plurality-of balancingartificial lines or networks N1, N2, N2, N1, N2, N2, N., vand N8,eachone of said networks being adapted to suitably balance one of saidtransmission lines.v The networks N1, N2,

2, N2, N ,1, N 2, N7 and N2, are connected to the network side of therepeater R2 by means of conductors branching o therefrom at the frontand back contacts of the relay 10, and at the front and back contacts ofrelays 11 and 12 and at the front and back contacts of relays 13, 14, 15and 16. f

Connected to the conductor terminating in the sleeve of .the'plug P2 isshown the relay `30 which has a high and a low resistance winding andwhich becomes energized whenever the Jplu P2 is inserted in one ofthe'jacks J1, 2, i, J2, J2, J2, J1 and 8. Associated with relay .30 is amaster relay MR. Similar master relays MR and MR etc., are providedl forother re eaters. In order that a repeater such as R may select networks,the corresponding master relay MR must be energized and remain energizeduntil the networks are selected for both ends of the repeater. Thecircuits of these master relays are sol arranged that when the masterrelay of one repeater isv energized, no other master relay can beoperated until the master relay which is enerf gized is restored tonormal at the end of a Consequently, but one repeater may selectnetworks at any given instant. Controlled by the master relay MR .is therelay 32 and the slow acting relays 33 and 34. The relay 32 serves toplace the relays A, B and C andthe network selecting relays 10, 11, 12,13, 14, 154 and 16 which are connected in parallel therewith inacondition'to be operated. Connected to conductors terminating at thesleeve contacts of the jacks J1, J2, J2, 2, J2, J2, J7 and J1, are themarginal relays 1, 2, 3, 4, 5, 6, 7 and 8 respectively. V The operationof these relays is dependent upon the actuation of relay shortcircuiting ot' the in of rela 30.

nder t e control of each of these marginal relays is a separateseries ofselecting relays, as, for example, under control ofrelay 2 is the relay2C, under the control of relay 4 are the relays 4B and 4C, and under thecontrol of relay 8 are the relays 8A, 8B

32 and the subsequent high reslstance wlndand 8C. Whenever one of therelays 5A, 6A, 7A or 8A is caused to be energized by the operation ofits marginal relay, a ground will be connected to the controllingconductor. 17, and a circuit will be completed through the windings ofrelay A, and such network controlling relays as are connected inparallel therewith. Vhenever one ot' the relays 3B, 4B, 7B or 8B iscaused to be energized by the operation of its controlling relay, aground will be connected to the controlling conductor 18 and a circuitwill be completed through the windings ot' rclay B, and the networkselecting relays which are connected in parallel thereto. Whenever oneof the relays 2C, 4C, 6C or 8C is caused to be energized by .the opera`tion of its controlling relay, a ground will be connected to thecontrolling conductor l!) and acircuit completed through the windings ofrelay C and the network controlling relaysl connected in parallelthereto.v

The artificial lines N1, N2, N11, N2, N2, N11, N7 and N2 are adapted tobalance other transmission lines similar in ty )e to the linesillustrated las `L1, L2, L11, i2, L2, L11, L., and L11. Connected toeach of the jacks at which such lines might terminate would be a relaysimilar to the relays l, 2, 3, 4, 5, 6, 7 and 8. "The relays connectedto lines of the same type, for exam-ple, as the line L2, would havetheir contacts connected in parallel with those of relay 2 to theconductor 21. The relays connected to lines of the same type, forexample, as the line Lm would 'have their contacts connected in parallelwith those of the relay to the conductor 25. By employing sucharrangements the cord circuit repeater of this invention will not belimited to use with only one transmission line of each type shown .butmay be employed to make coimcctions with a plurality of transmissionlines ol' each type.

The invention may now he more fully nn- .derstood from the followingdescription ot' its operation: lf a connection is desired through thecord circuit repeater R with one of the transmission lines, such forexample as the transmission line L2, the plug P2 is inserted in the jackJ2 and the following cirto ground. The closing of this circuit willenergize relay 30, but as the circuit includes the high resistancewinding of relay 30 the-marginal relay 2 will not be energized. Theoperation of relay 30 closes the following circuit; fromground, righthand contact of relay 30,"corr 1f dl 1ctors 38 and 39, left hand Windingof master relay MR, over conductor 40, contacts of relay MR, and overconductor 41 including the contacts of other master relays of otherrepeaters, such as relays MR and MR etc., to battery and ground. Theclosing of this circuit will energize relay MR which will in turn openthe above described circuit at its right hand contact and will becomelocked up as follows; from ground and battery,v conductor 41 includingcontacts of relays such as MR.l 'and MR', contact and armature of relayMR, right hand winding of relay MR, conductors 42, 43 and 38, armatureand contact of relay 30, to ground. Upon the energization of relay theprocess of network selection for repeater R may be started. It will beseen however, that if another repeater was engaged at the `same time inselecting networks and the master relay of that repeater, such forexample as relay MR', was energized the above described circuit throughrelay MR would be held open at the contacts of relay MR and relay MRcould not bey energized and the network selecting process could not bestarted until the completion of the net-` work selecting of the otherrepeater and thev subsequent denergization of the relay M R. By thismeans but one network selecting process may take' place at a time andinter-- ference and false selection is obviated. f

Upon the operation of the master 'relay MR the process of selecting asuitable network to balance a line such for example as L2 is started bythe closing of the following circuit; from ground and battery, conductor41, contact and armature of relay MR, conductor 44, winding of relay 32,conductors 45, 43, and 38, armature and contact of relay 30, to ground.This operates the relay 32 and 'closes the following circuit; fromground and battery, left hand armature and contact of relay 30,conductor 46, contact-of relay 35, conductors 47 and 48, right handContact and armature of relay 32, conductors 49 and 50, and thencethrough the windings of relays 36 and 37 and. to ground, therebyoperating relays 36 and 37. Relays 36 and 37 pull up their armatures anda potential is thereby applied from conductor 50, over the contacts ofrelays 36 and 37, and over! 432 also closes the following circuit; fromground and battery, conductor 60, left hand armature and contact ofrelay 32, conductor 61, low resistance winding of relay 30, sleeveconductor of plug P2, sleeve contacts of plug P2 and jack J2, sleeveconductor of jack J2, winding of marginal relay 2, to ground. As thiscircuit short circuits the high resistance winding of rel-ay 30'the marinal relay 2 will now be operated and the ollowing circuit closed; fromground and battery, Winding of relay 2C, conductor 21, contact andarmature of marginal relay 2, to ground. This will operate relay 2Cwhich will pull up its armature and thereby ap lyv ground to its contactand to the controlhn conductor 19. As has been previously pointed out apotential has been applied to the controlling conductor 19 and to therelay C and the network relays 13, 14, 15 and l16 connected in paralleltherewith. Consequently the operation of relay 2C and the connection ofground to controlling conductor 19 will complete the circuit throughrelays C, 13, 14, 15 and 16, and will cause them to become ener-l gized.Upon the operation of relay 13 thel network N2 suitable for balancingthe line L2 will be connected to repeater R by means f of conductors 65,front contacts of relay 13',

conductors 64, back contacts of relay `11, conductors 63, back contactsof relay 10. The relay C and the relay 13 connected in paralleltherewith, are maintained in an energized condition while the repeater Ris associated with the line L2 by means of the following lockingcircuit; from ground, right hand armature and contact of relay C,winding of Vrelay-C, left hand contact and armatu'rle of relay C,conductor 47, armature and contact of relay 35, conductor 46, contactandi' armature of relay 30, to battery and ground. v

Alfterfthe proper network has been selected and associated with therepeater R the apparatus is restored to norm-al as follows; connected toconductor 49 of the previously .described circuit 'closed through relays36 and 37 is the conductor '66 and the slow operating relay 33., whichwill function at an interval after the completion of the above mentionedcircuit through relays 36 and 37. The operation .of relay 33 closes acircuit from conductor 49, over conductor 67, contact and armature ofrelay 33, conductor 68,' winding of slow operating relay 34 to ground.The closing of this circuit will cause the slow operating relay 34 tofunction at an interval after the functioning of relay The operation ofrelay 34, opens at Contact point 69 the abo've men- 37 and therebyreleases said relays. The

operation of relay 34 by attracting its right hand armature opens atcontact point the previously described short circuit about the highresistance winding of relay 30 and thereby denergizes the marginal relay2 in the sleeve circuit of the line L2 and causes the denergization ofrelay 2C; The operation of relay 34 also closes the `following' circuit;from ground -and battery, right hand contact and armature of relay 34,conductor 71, winding of relay 31, to ground. This operates relay 31which pulls up its armature and opens at Contact point 72 the previouslrelay M and rela 32, thereby denergizing said relays. en the connectionis completed and -lthe plug P2 is withdrawn from the line the relay 30is denergized and opens at its left hand contact the previously tracedlocking Ycircuit for the relay C and the relays 13, 14,715 and 16connected in parallel therewith, thereby restoring said relays tonormal. Should the plug P2 be inserted in a line jack again within ashort interval and should the relay 34 be slow in releasing, the relay34 might Aremain continuously operated. Accordingly when the plug P2 iswithdrawn from the line and the relay 30 is denergized the followingcircuit is completed; from ground, right hand contact of relay 30,conductor 73, winding' of relay 35, conductor 74, armature and contactof relay 34, to battery and ground. The closing of this circuit operatesrelay 35 which holds'open at its contact the previously traced circuitfrom battery about the winding of relay 34, and thus prevents thecontinuous operation of that relay.

. lf a connection is desired through the cord circuit repeater R withanother of the lines, lsuch for purposes of illustration as the line L8,the plug P2 is inserted in the jack J8 and the operation will besubstantially similar to that previously described in detail for aconnection with the line L2. 1n the same manner as reviously 'pointedout the master relay land its associated relays will function and apotentialwill be applied to relays A, B and C, and the network selectingrelays 10,'11, 12, 13, 14, 15 and 16, connected in parallel therewithand to controlling conductors 17 18 and 19.- The marginal relay 8 in thesleeve circuit of line L, will be operated in a manner similar to theoperation of marginal relay 2 and will serve to operate relays 8A, 8Band 8C, in a manner similar to the operation of relay 2C. The operationof 4relays 8A, 8B and 8C will connect ground over their contacts to thecontrolling conductors 17, 18 and 19 and thus complete circuits forrelays A, B and C, and the relays 10, 11, 12, 13, 14, 15 and 16 and allof these relays described circuits closed about will be energized andlocked up in amanner previously pointed out with respect to relay C andrela s 13, 14, 15 and 16. The

proper network 8 to balance line L,3 ,will now be connected to repeaterR vover conductors 62, front contacts ofrelay 10, conductors 75, frontcontacts of relay 12, conductors 76, front contacts of relayv 16, and

over conductors 77.

hen a connection is desired with any one of the other transmission linesand the plug P2 is inserted in the jack at which said line terminates,it will be seen that in a similar manner the proper network to suitablybalance said transmission line will be automatically selected andconnected to the cord circuit repeater. The apparatus will be restoredto normal upon the completion of the process of network selection andupon the completion of a connection in the same ymanner as pointed outfor a connection with the line L2.

It is pointed out that other repeater cord circuits, such as thoseassociated with the relays, MR and MR, may be connected with the linesL, to L8 inclusive. ln such instances the network selecting arrangementssuch as the series of parallel relays associated with said repeaterswill be controlled by the relay arrangements associated with the linesL, to L2 in a manner similar to that already described. To accomplishthis the .Controllingconductors 17, 18 and 19 are extended to beconnected to the windings at the repeater cord circuits of relayssimilar to the relays A, B and C. The eX- tension of these controllingconductors for this purpose is illustrated by the arrowheads at theextreme right of Fig. 2.

p While the invention has been disclosed as embodied in certain specificarrangements which have been deemed desirable, it will be understoodthat it may be embodied v of said series of rela-ys connected inparallel,

the connection of said artificial lines to said repeater being effectedover the contacts of 011e of the relays of each of said series ofparallel relays.

2. A plurality of transmission lines. a repeater for making connectionstherewith, a plurality of balancing artificial lines associated withsaid repeater, a pluralityof relays connected in parallel controllingthe connection of said artificial lines with said repeater, means forapplying a potential to the normally open circuits including thewindings of said series of relays connected in parallel, and meansassociated with the terminal arrangements of said transmission lines forclosing various combinations of said normally open'circuits.

3. A plurality of transmission lines, a repeater for making connectionstherewith, a plurality of balancing artificial lines associated withsaid repeater, a plurality of series of relays connected in parallelcontrolling the connection of said artificial lines t0 said repeater, anormally open circuit for each of said series of relays connected inparallel, a controlling conductor connected to each' of said circuits,means for applying a potential to all of said circuits, and means forconnecting a ground 'to various combinations of said controllingconductors.

et. A plurality of transmission line/s, a repeater for makingconnections therewith, a plurality oft' balancing artificial linesassociated with said repeater, a plurality of series of relays connectedin parallel controlling the connection of said arti'icial'lines to saidrepeater, a normally open circuit for each of said series of relaysconnected in parallel, a; controlling conductor connected to each ofsaid circuits, means operative upon the connection of the repeater toany oi said transmission lines for applying a potential to all of saidcircuits, a source of electrical energy associated with said repeater, aseparaterelay connected to each of the terminal arrangements of saidtransmission lines, the relay associated with each of said transmissionlines responding when the repeater is associated with said line, andmeans under the control of said last mentioned relays for connecting aground to various combinations of said controlli-ng conductors. y

5. A plurality of transmission lines, a repeater for making connectionstherewith, a plurality of series of 'relays connected in parallel,conductors leading from the repeater to the armatures f a relay includedv in one of said series of relays connected inY parallel, conductorsle'ading from the front and back contacts of said last mentioned relayto the armatures of relays included in another of said series of relaysconnected Ain parallel, conductors leading from the front and backcontacts of said last mentioned relays to the armatures of relays1ncluded in another of said series of relays connected in parallel,conductors leading from the front and back contacts of said lastmentioned relays, artificial lines associated with said last mentionedconductors, and means to operate various combinations of said series ofparallel relays for selecting and connecting an artificial line to saidrepeater. y

6. A plurality of transmission lines, a plurality of repeaters formaking connections therewith, a plurality of artificial lines associatedwith each repeater, a plurality of series of relays connected inparallel associated with each repeater for controlling the selection andconnection to said repeater of one of the artificial lines associatedtherewith, a plurali-ty of controlling conductors, each controllingconductor being associated with a certain of said series of relaysconnected in parallel of each repeater, means associated with eachrepeater whereby when a repeater is connected with a line the pluralityof series of relays connected in paral-V ,with certain of said series ofrelays connected in parallel of each repeater, means associated witheach repeater whereby when a repeater is connected with a line theplurality of series of relays connected in parallel associated with thatrepeater are conditioned for operation, and means individual to the linefor operating the relays of said repeater associated with a plurality(if said controlling conductors.

8. ln a signaling system, aplurality of lines ofdifferent types,repeaters for interconnecting said lines, balancing networks for eachtype of line, a plurality of selecting relays for each repeater,controlling relays for said selecting relays associated with eachrepeater, 'means responsive to the association of a repeater with a lineto cause said controlling relays of that repeaterto prepare circuits forall of the selecting relays of that repeater, means determined by theline with which the repeater is associated for completing a circuit fora selecting relay, and means responsive to the actuation of saidselecting relay to associate a balancing network with the repeater, andmeans to 'hold open the circuits of said controlling refor saidselecting relays lassociated with each repeater, means responsive to theassociation of a repeater with a-line to cause said controlling relaysof that repeater to prepare circuits for all of the selecting relays ofthat repeater, means determine by the line with which the repeater isassociated for completing circuits for a combination of the selectingrelays, and means responsive to the actuation of said selecting relaysto associate a balancing network with the repeater.

10. In a, signaling system, a .plurality of lines of different types,repeaters for interconnecting said lines, balancing networks foreachtype of line, a plurality of selecting relays for each repeater,controlling relays for said selecting relays associated with eachrepeater, means responsive to the association of a repeater with a lineto cause said controlling relays of that repeater to prepare circuitsfor all of the selecting relays of that repeater, means determined bythe line with which the repeater is associated for conipleting a circuitfor a selecting relay, mea-ns responsive to the actuation of saidselecting relay to associate a balancing network with the repeater, andmeans to lock up said selectin relay.

11. n av signaling system, a plurality of lines of different types,repeaters for interconnecting said lines, `balancing networks for eachtype of line, and a relay individual v -to each repeater, operativevwhen the corresponding repeater is used for interconnecting lines, tocause the selection of balancing. networks for the lines and to preventthe selection of networks by other repeaters while that repeater isselecting.

12. In a signaling system, a ,plurality of lines of different types,repeaters for inter- 1 connecting said lines, balancing networks foreach type of line, and a relay individual to-each repeater, operativewhen the correspending repeater is used for connecting lines, to causethe selection of balancing networks for the lines, the circuits of saidrelays for the several repeaters being so arranged that when the relayof one repeater is energized. during the process of network selection,the circuits of the relays of other .repeaters will be held open untilthe process of selection for that repeater ispcompleted.

13. In a telephone repeater system, in combination, two telephone lines,a plurality of balancing lines, two repeaters for use in establishingindependent telephone connections, means for associating the repeaterswith the respective telephone lines, Ymeans for selecting andassociating one of the balalicin lines with each repeater foribalancingt le. respectivel associated line, means operative upon the associationof the repeaters with the telephone lines for renderlng the selectingmeans effective for selecting a balancing line for one repeater, andmeans operative after such selection for rendering the selectingmeanseffective for selecting another balancing line for the other repeater.

14. In a. telephone repeater system, in

combination, two telephone lines, a plurality of balancing lines, tworepeaters for use in establishing independent telephone connections,means for associating the repeaters with'the respective tele hone lines,means for selecting and associatl ga balancing line with each repeaterfor balancing the respective'as'sociated lines, a switching relayoperatin upon the association of the repeaters with oth lines forcausing the selecting mgans to select and associate a balancing linewith one repeater, and a switching relay rendered effective upon theselection of the one balancingline for causing the selecting means toselect and connect with the other repeater another balancing-line.

n testimony whereof, I have signed my name to this specification this15th day of May, 1919.

' OLIVER B. JAcoBs.

